I have gotten the old SIS drivers to compile and run in 16.04. I'm looking for the mods to enable support for the 671 and 771 GPUs if anyone knows where the source is.
The existing drivers support:
SIS: driver for SiS chipsets:
SIS5597/5598, SIS530/620, SIS6326/AGP/DVD, SIS300/305, SIS630/730, SIS540, SIS315, SIS315H, SIS315PRO/E, SIS550, SIS650/M650/651/740, SIS330(Xabre), SIS660/[M]661[F|M]X/[M]670/[M]741[GX]/[M]760[GX]/[M]761[GX]/[M]770[GX], SIS340
SIS: driver for XGI chipsets:
Volari Z7 (XG20), Volari V3XT/V5/V8/Duo (XG40)
More details here for the brave
If the code for the 671 and 771 shows up and I find time to merge it in, full details will be posted here.